The present invention relates to an apparatus and a method for managing power, mainly for a computer system, and especially to an apparatus and a method whereby it is possible to so manage power for a computer system wherein there is a plurality of peripheral devices, which can be simultaneously operated, that the total power consumed by such devices does not exceed a predetermined capacity.
Conventionally, with a computer system that permits the simultaneous execution of jobs by a plurality of peripheral devices, such peripheral devices are independently controlled, and the amount of,power supplied for the collective execution of jobs by these peripheral devices is the total of the maximum power consumed by each of these peripheral devices when executing a job.
For example, for a computer system in which a floppy disk drive and a CD-ROM drive are included as peripheral devices, the power supply capacity for a power source is so set that it equals the total of the maximum power required for the operation of the floppy disk drive and that required for the operation the CD-ROM drive. This is done in order to prevent the overloading of the power source under all permissible operating conditions. Under normal operating conditions, however, as maximum power consumption by both the peripheral devices will seldom occur at the same time, this results in the power source not being used efficiently. Furthermore, the power consumption required is so large that providing it interferes with attempts to reduce the size and weight of the computer system as a whole.